How Do Giraffes Drink Water and Does a Giraffe Ever Black Out When it Bends Over?

July 18, 2014 by Karen Hill | Filed Under: Animals

A giraffe holds its legs out straight to the side when bending to get a drink of water.

Giraffes have a unique circulatory system, and its heart, which can weigh up to 22 pounds, must generate about twice the normal blood pressure for an average large mammal to maintain blood flow to the brain.

The giraffe is also equipped with an amazing network of veins and valves in the neck that keep blood from ever flowing too fast or too slow, whether the animal is bending over or getting back up.

In the upper neck, a complex pressure-regulation system called the “rete mirabile” prevents excess blood flow to the brain when the giraffe lowers its head to drink.

When they begin to get full, the pressure is felt by the giraffe in time for him to right himself and then the process works in reverse, the veins and valves partially close off, so blood doesn’t flow back down into the body too rapidly.

Giraffes have a very tight, thick skin over their lower legs which maintains high pressure very similar to a pilot’s g-suit.

If you watch a giraffe taking a drink, you will see that he doesn’t stay down indefinitely, but raises his head now and again.